# Claude Haiku 5.5 vs GPT-6 Luna

Claude Haiku 5.5 (Anthropic) and GPT-6 Luna (OpenAI) compared on the facts each vendor publishes. Price does not decide it: both list $0.1 in and $0.5 out per 1M tokens. For very long inputs, GPT-6 Luna lists the larger context window: 1.05M tokens against 1M. We have not run either model: every value below is Reported, with a link to its source.

Updated: 2026-10-29 · Canonical: https://theagenticweekly.com/compare/claude-haiku-5-5-vs-gpt-6-luna · Evidence: Reported (not run by us)

## Specs

| | [Claude Haiku 5.5](https://theagenticweekly.com/models/claude-haiku-5-5) | [GPT-6 Luna](https://theagenticweekly.com/models/gpt-6-luna) |
|---|---|---|
| Price (as listed) | $0.1 in / $0.5 out per 1M tokens ([source](https://platform.claude.com/docs/en/about-claude/models/overview)) | $0.1 in / $0.5 out per 1M tokens ([source](https://developers.openai.com/api/docs/models/gpt-6-luna)) |
| Context window | 1,000,000 tokens (1M) ([source](https://platform.claude.com/docs/en/about-claude/models/overview)) | 1,050,000 tokens (1.05M) ([source](https://developers.openai.com/api/docs/models/gpt-6-luna)) |
| Max output | Not published | 128,000 tokens ([source](https://developers.openai.com/api/docs/models/gpt-6-luna)) |
| Input | text, image ([source](https://platform.claude.com/docs/en/about-claude/models/overview)) | text, image ([source](https://developers.openai.com/api/docs/models/gpt-6-luna)) |
| Output | text ([source](https://platform.claude.com/docs/en/about-claude/models/overview)) | text ([source](https://developers.openai.com/api/docs/models/gpt-6-luna)) |
| Licence | Proprietary (API) ([source](https://platform.claude.com/docs/en/about-claude/models/overview)) | Proprietary (API) ([source](https://developers.openai.com/api/docs/models/gpt-6-luna)) |
| Released | Oct 7, 2026 ([source](https://www.anthropic.com/news)) | Sep 22, 2026 ([source](https://developers.openai.com/api/docs/changelog)) |
| Status | generally available | generally available |
| API id | claude-haiku-5-5 ([source](https://platform.claude.com/docs/en/about-claude/models/overview)) | gpt-6-luna ([source](https://developers.openai.com/api/docs/models/gpt-6-luna)) |

## How to choose

- Price does not decide it: both list $0.1 in and $0.5 out per 1M tokens.
- For very long inputs, GPT-6 Luna lists the larger context window: 1.05M tokens against 1M.
- Claude Haiku 5.5 is newer, by 15 days.

## Benchmark snapshots (not our tests)

- Terminal-Bench 4.0 official leaderboard (independent, 2026-10-26, [source](https://www.tbench.ai/leaderboard/terminal-bench/4.0)): GPT-6 Luna (Codex, max) 16.4%
- SWE-bench Pro (Public), as reported by the vendors (vendor-reported, 2026-10-26, [source](https://benchmarkregistry.org/benchmarks/swe-bench-pro/public)): Claude Haiku 5.5 (max) 64.8%

## FAQ

**Which is cheaper, Claude Haiku 5.5 or GPT-6 Luna?** Claude Haiku 5.5: $0.1 in / $0.5 out per 1M tokens. GPT-6 Luna: $0.1 in / $0.5 out per 1M tokens. Both prices are the vendors' own listed prices on the date each model was last verified.

**Which has the bigger context window?** GPT-6 Luna, with 1,050,000 tokens against 1,000,000.

**Which is better for coding?** We have not tested either. Sourced snapshots: Terminal-Bench 4.0 official leaderboard (independent, Oct 26, 2026): GPT-6 Luna (Codex, max) 16.4%; SWE-bench Pro (Public), as reported by the vendors (vendor-reported, Oct 26, 2026): Claude Haiku 5.5 (max) 64.8%. Scores from different boards are not comparable with each other.

**Are Claude Haiku 5.5 and GPT-6 Luna open source?** Claude Haiku 5.5: Proprietary (API), no downloadable weights. GPT-6 Luna: Proprietary (API), no downloadable weights.

**Did you test Claude Haiku 5.5 and GPT-6 Luna?** No. This page is Reported: every fact is read from the vendor page linked beside it, and benchmark numbers come from the named boards.

## How to cite

Agentic Weekly, "Claude Haiku 5.5 vs GPT-6 Luna", updated 2026-10-29, https://theagenticweekly.com/compare/claude-haiku-5-5-vs-gpt-6-luna